Ecology Flashcards
Ecology
is the rigorous study of climate and interactions with other species in understanding how these influence the distribution and abundance of organism
Organismal Ecology
how does an organism’s structure, physiology, and behavior affect its survival in the environment
Ex. How do flamingos mate?
what mechanisms are involved in mate selection
Population Ecology
analyses factors that effect population size and how it changes through time
Ex. What environmental factors affect the reproductive rate of flamingos?
Community Ecology
examines how interactions between species, such as predation and competition, affect community structure and organisation
Ex. What factors influence the diversity of species that interact within an area?
Ecosystem Ecology
emphasises energy flow and chemical cycling between organisms and their environments
• Ex. What factors control photosynthetic productivity in this aquatic ecosystem?
Landscape Ecology
focuses on factors controlling exchanges of energy, materials, and organisms across multiple ecosystems
Ex. To what extent do nutrients from terrestrial ecosystems affect organisms in this lake?
Global Ecology
examines how the regional exchange of energy and materials influences the functioning and distribution or organisms across the biosphere
Ex. How do global patterns of air circulation affect global distribution of species?
How does earths climate vary?
Earth’s climate varies by latitude and season
And is changing very rapidly!
climate
the long term prevailing weather conditions in an area
The main driver of organismal distribution
Insolation
is the intensity of sunlight (energy) in a given area during a period of time
What factors determine the climate?
Solar energy ( Insolation)
Seasonality
Water Bodies
Mountains
Where is insolation higher?
highest at equator because we get the most amount of direct sunlight from space
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Higher temps in the tropics evaporate more water, causing warm air masses to flow to the poles
As they move over tropics, condense and release moisture (rain)
Dry air creates deserts (~30°N/S)
Seasonality
The Earth’s tilt toward the sun and annual rotation around the sun causes strong seasonal variations in middle to high latitudes (affects insolation)
Changes day length, solar radiation, temperature
Can cause seasonal shifts in rainfall amounts, wind patterns, ocean currents
Water Bodies
Ocean currents affect climate by heating and cooling overlying air masses
Coastal regions are also generally wetter than intercontinental areas
Supports huge diversity of coniferous rainforests(Giant redwoods and Sitka spruces along West Coast), or fog forests of Newfoundland
How does specific heat capacity moderate climate?
The specific heat capacity of water means water moderates local climates
- On hot days, land is warmer than water and warmer air masses draw in cooler air masses from water to land
- At night, water cools more slowly than land, drawing cooler air from the land away and warming it with the warmer air from water
Mountains
When warm air meets a mountain, the air rises and cools
The windward side receives abundant rainfall as the air moves up the mountains
On the leeward side, air is now cooler and descends, picking up moisture and resulting in a “rain shadow” (drier
Produces the world’s deserts and also Alberta Chinooks
What do mountains also affect?
Also affect sunlight
South-facing slopes in the N. hemisphere receive more sunlight than north-facing slopes, and are thus warmer and drier
Spruce and conifers grow on the cooler north-face and shrubby, drought-resistant plants grow on the south-face
Every 1000m increase in elevation drops the temperature by ~6°C
microclimate
Very fine, localized patterns in climatic conditions
Weather
day to day activity
What factors cause microclimate?
Abiotic–non-living
Biotic-living
Abiotic
–non-living
Chemical and physical attributes
Temperature, light levels, water , nutrients
Biotic
Forest trees moderate climate below them by casting
shade, reducing wind, reducing surface evaporation
Creates a cooler, humid microclimate
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The burning of fossil fuels and deforestation have dramatically changed the Earth’s climate in a directional shift from Earth’s normal climate -> climate change
The burning question becomes then if current global species will be able to adapt to these climatic shifts
What can global climate change affect?
can affect the interactions of life all around Earth (biosphere)
What questions do ecologists ask?
Ecologists ask not only where are organisms found, but also why?
What factor can affect distribution?
Physical location of the land can affect distribution
• Kangaroos in Australia are found no where else on Earth
where are organisms found, but also why?
Maybe it’s because they never had a chance to
disperse
What evidence do ecologists use?
Ecologists can use molecular evidence to unravel evolutionary pasts and historic dispersal routes
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As climate warms, natural range expansion can occur, however abiotic factors can limit how much they expand their ranges
Range expansions can have huge affects
Coyotes expand into new territories, reducing deer populations
Reduced deer populations affect tick populations and reduce the prevalence of Lyme-disease (if humans don’t control coyote populations
Coyotes can also hybridise with wolve “coy-wolf”, ie Eastern coyote
What factors can affect dispersal?
abiotic and biotic
What abiotic factors affect dispersal?
Temperatures, salinity, water levels, sunlight, soil nutrients/composition can also prevent organisms from tolerating and surviving in new environments
fundamental niche
The abiotic factors that permits an organism to survive in an area
Populations
are a group of individuals from the species inhabiting the same general area
Rely on the same resources, are influenced by the same environmental factors, and are likely to interaction and interbreed with each other
Density
is the # individuals per unit area or volume
How are populations described?
Described via boundaries and size (ie # individuals in an area)
What are different methods sued to determine density?
mark-recapture, counting a subset per unit area and extrapolating, counting proxies (tracks, fecal piles, number of nests, etc)
Immigration
influx of new individuals from another population
Emigration
movement of individuals out of a population to
other locations
Dispersion
is the pattern of spacing among individuals
Clumped
aggregate in patches (ie plants and fungi due to soil conditions)
most common
Uniform
evenly spaced (i.e. territorial animals, flocks of birds)
Random
spacing is independent of other individuals (ie dandelions)
What are the different dispersion patterns?
clumped
uniform
random
Demography
is the study of vital statistics of populations and how they change over time
Birth rates
frequency of live offspring born in a population
Death rates
frequency of deaths in a population (ie Mortality rate during a given time frame
When looking at birth and death rates which population do we look at?
Usually just look at females since only females physically produce offspring
survivorship curve
Can represent the survival data as a survivorship curve
Plot of the proportion of individuals in a cohort still alive at each age
What are the different types in a survivorship curve?
Type I – flat at start, low death rates early on
• Typical of large mammals that produce few offspring but high investment in parental care
- Type II – intermediate, constant death over lifespan
- Typical of ground squirrels and small animals
- Type III – sharp death rate at start, declines as aging increases
- Typical of organisms that produce abundant young (fish, plants,fungi etc),and do not provide much for parental car